Air conditioning apparatus



Feb. 7, 1950 H. o. KIRKPATRICK 2,497,028

AIR CONDITIONING APPARATUS Filed June 3, 1946 2 Sheets-Sheet 1 Hill] IHIH Hlll Hewey 0. Mae/ 4 re/ac 1950 H. o. KIRKPATRICK 2,497,028

AIR CONDITIONING APPARATUS 2 Sheets-Sheet 2 Filed June 3, 1946 gwuwwfom HENRY O. fla Pnrt/cz Patented Feb. 7, 1950 2,497,028 AIR CONDITIONING arraaarus Henry 0. Kirkp trick, Detroit,

Advance Manufacturinglnc corporation of Michigan Micla, asoignor to Detroit, Mich, a

Application June 3, 1946, Serial No. 673,990

(Cl. 6H)

11 Claims.

This invention relates to air conditioning apparatus.

One of the objects of this invention is to provide air conditioning apparatus rendering it possible to more efliciently heat or cool the interior I of an enclosure and maintain the atmosphere of the enclosure at a predetermined temperature. 4

this invention is to provide air conditioning apparatus composed of a rela- A tively few simple parts capable of being compactly arranged and readily controlled from a relatively simple centrally located panel.

Still another feature of this invention is to provide air conditioning apparatus embodying an internal combustion engine as the prime mover and constructed to employ the waste heat from the engine to improve the efliciency of the equipment.

A still further object of this invention is to provide air conditioning apparatus of the above general type having a heat exchange unit in the enclosure to be conditioned and connected in the system to selectively operate as an evaporator and a condenser.

The foregoing as well as other objects will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing, wherein:

Figure 1 is a semi-diagrammatic view of air conditioning apparatus embodying the features of this invention;

Figure 2 is a wiring diagram of the control circuit; and

Figure 3 is an elevational view of the master control switch.

Upon reference to Figure 1 of the drawing, it will be noted that the reference character l0 designates generally air conditioning apparatus of the type adapted to cool or heat the atmosphere within an enclosure to maintain a predetermined temperature within the enclosures regardless of the temperature of the atmosphere outside of the enclosure. tioningapparatus comprises a refrigerant compressor II, a prime mover in the form of an internal combustion engine I! for operating the compressor, a refrigerant condenser IS, a heat exchange unit I4, and an evaporator l5.

Briefly, the air condi- The heat exchange unit ll may be of any suitable construction capable of emciently exchanging heat with the surrounding atmosphere and is suitably supported in an enclosure i6 containing the atmosphere which it is desired tomaintain at a predetermined temperature. The air or atmosphere within the enclosure is circulated through the heat exchange unit it by a fan ll supported at one side of the heat exchange unit, and driven by an electric motor II.

The compressor I 1, internal combustion engine 12, condenser l3 and evaporator is are suitably supported within a compartment 18 having an entrant opening for air 19 throughthe bottom wall thereof. One end wall 20 of the compartment I8 is formed with an opening 2| therethrough and the passage of air through this opening is controlled by a closure 22 comprising a plurality of louvres 23. The louvres are operatively connected to a control arm 24 pivotally supported on the wall 20 of the closure for convenient manipulation. The louvres 23 are shown in their open positions in Figure 1 of the drawing, and may be readily closed by merely swinging the arm 24 to its dotted line position shown in Figure 1 of the drawings. The opposite end wall 25 of the compartment It has an opening ll therethrough, and the passage of air through the opening 26 is controlled by a closure 21 comprising a plurality of louvres 28 normally held in their open positions by means of a spring 28. A control arm 30 is suitably pivotally supported on the end wall 25 for convenient manipulation, and is operatively connected to the louvres II for closing the same. A second opening 3| is formed in the end wall 25 above the opening 2, and this opening communicates with an air duct 32 arranged adjacent the internal combustion engine I2 and surrounding the exhaust conduit 33 for the engine. An opening 34 is formed at the bottom of the delivery end portion 35 of the air duct, and the passage of air through this opening is controlled serves to close the opening 3| when it is swung to its open position relative to the opening 34. The damper 36 arm 30 for operation by the latter. The arrangement is such that when the arm 30 is in its full line position shown in Figure 1 of the drawing, the damper 36 closes the opening 34 and the louvres 28 are in other hand, when the arm line position to close the louvres It is'swung upwardly to open the opening 34 and to close the opening it.

by a damper 3B, which also is operatively connected to the their open positions. On the 30 is swung to its dotted 28, the damper V side of a cranking limiter switch 64. The other side of the switch 64 is connected to the terminal B of a voltage regulator and is also connected to nected to the high pressure side of the compres- Y sor II by a conduit 36, and the lower end of the condenser i3 is connected to\a receiver tank 46. The receiver tank 46 is suitably supported in the compartment l6 below the condenser l3 and is' connected to the receiving or upper end of the heat exchange unit I 4 by a conduit 4|. An ex-,

pansion valve 42 is connected in the conduit 4| adjacent the receiving end of the heat exchange unit H in accordance with conventional practice. The expansion valve 42 is bypassed by a conduit 43 and a valve 44 is suitably connected in the bypass. The lower or return end of the heat exchange unit I4 is connected to an auxiliary receiver tank 44 by a conduit 45. The auxiliary receiver tank 44 is suitably supported in the compartment l6 and is connected to the low pressure sides of the compressor II by a conduit 46. A control valve 41 is connected into the conduit 46 between the receiver tank 44 and compressor Ii.

The evaporator l5 may also be of any accepted design and is supported in the compartment l6 adjacent the opening 26 through the wall 25 of the compartment. The upper or receiving end of the evaporator I5 is connected to the conduit 46 by a conduit 46 and an expansion valve 46 is connected in the conduit 46. As shown in Fig ure 1 of the drawing, the conduit 46 is connected to the conduit 46 between the auxiliary tank 44 and the valve 41. The return or lower end of the evaporator I 5 is connected to the low pressure side of the compressor by a conduit '56.

The internal combustion engine i2 is supported at the inner side of the evaporator l5, and is provided with a fan 5| for drawing air through the evaporator. As will be more fully hereinafter described, the internal combustion engine is equipped with the usual ignition means 52, and is also provided with an electric starting motor 53.

The air conditioning apparatus described above is controlled from a central panel by the control circuit diagrammatically shown in Figure 2 of the drawing. This control circuit comprises a three-pole double-throw switch 54 having a panel 65 provided with three push buttons indicated in Figure 3 of the drawing by the reference characters 56, 51 and 66. As will be presently described, the apparatus may be operated to lower the temperature of the atmosphere in the enclosure l6 by pushing the button 66, and may be operated to raise the temperature of this atmosphere by pushing the button 51. The button 66 may be operated to discontinue the operation of the air conditioning apparatus. The operation of the apparatus may also be interrupted by a double-throw switch 61' and the latter, in turn, is automatically operated by a thermostatsuitably supported in' the enclosure l6, so as to be responsive to variations in temperature of the atmosphere within the enclosure.

The switch 64 has three movable contact blades 66, 66 and 6!. The terminal of the blade 66 is electrically connected to the terminal 62 for the movable contact blade 63 of the switch 61' and the terminal 62 is electrically connected to one the negative pole of a suitable 'storalie battery 66. The switch blade. 66

is alternately engageable with the fixed contacts 66 "and 61. The fixed contact 66 is connected to one-end of a solenoid coil 66, and the opposite end of the coil is connected to the positive pole of the battery 66 through the ground 66. The solenoid 66 is operatively connected to the valve 41 and is adapted to open the valve 41 when the coil of the solenoid is energized. The terminal 61 of the switch 64 is electrically connected to one end of the solenoid coil 44 and is adapted to open this valve when the coil of the solenoid is energized.

The center terminal of the movable contact blade 66 is electrically connected to one side of a safety switch 12 having the opposite side connected to one side of a pressure switch 13. The switch 13 has a movable contact 14 which alternately engages contacts 16 and 16. The contact 15 is electrically connected to the solenoid coil 11 of the starter switch 16 and the contact 16 is electrically connected to the center terminal for the movable contact blade 6| of the switch 64.

The movable contact blade 66 alternately engages fixed contacts 11 and 16. The contact 11 is electrically connected to the flxedcontact 16 of the thermostat operated switch 61' and the contact 16 is connected to the other terminal 66 of the thermostat operated switch 51'. As stated above, the center terminal of the movable contact blade 6| is electrically connected to the fixed contact 16 of the pressure switch 13 and is also electrically connected to one end of a solenoid coil 6| having the opposite end connected to the ground 66. The solenoid 6| is operatively connected to a switch 62 having one side electrically connected to the terminal A of the voltage regulator and having the other side connected to the motor I1 for the fan l6.

The contact blade 6i alternately engages fixed contacts 63 and 64. The fixed contact 63 is a blank contact and the contact 64 is electrically connected to one end of a solenoid coil 66 having the opposite end connected to the ground 66. The solenoid 66 is operatively connected to a switch 66 having one side connected to the terminal A of the voltage regulator and having the other side connected to the motor 36 for the condenser fan 31.

Upon reference to Figure 2, it will be noted that one side of the starter switch 16 is connected to the negative pole of the battery 66, and the other side of the starter switch is connected to one end of the coil 61 for the starting motor 63. The other end of the coil 61 is connected to the terminal A of the voltage regulator. A second coil 66 of the starting motor 63 is connected at one end to the ground 66 and is connected at the other end to the terminal F of the voltage regulator. With this arrangement, the starting motor may be employed as a generator during operation of the internal combustion engine to supply electric current to both the motors l1 and 36.

The distributing system of the internal combustion engine is indicated by the reference character 62 and comprises the usual distributor 66. The distributor 66 is electrically connected to the various spark plugs of the engine and is also connected to an ignition coil 66. The ig- 5 nition coil II is electrically connected in the circuit to the pressure switch II by a conductor II.

Operation When it is desired to cool the atmosphere within the enclosureII', the louvres 2I and 2I are opened. Manipulation of the control arm II to open the louvres 2I swings the damper II to its closed position with respect to the opening II and opens the opening II. Also, the thermostat operated switch 51 is in a position wherein the movable contact II engages the fixed contact II, so that the fixed contact II of the switch II is energized. The switch II is then operated by pressing the push button II, with the result that the movable contacts II, II and II are respectively engaged with the fixed contacts II, II

and II.

As a result of the foregoing, the solenoid II is energized to open the valve I1, and the solenoid II is deenergized to permit the valve II to close. The safety switch 12 is normally closed by the spring I2, so that the ignition coil II is energized. Also, the pressure switch II is in a position wherein the fixed contact." is energized,

so that the coil II of the starter switch "II is also energized. As soon as the internal combustion engine is started, the pressure built up by the oil pump of the engine operates the pressure switch 13 to energize the fixed contact II and thereby closes the circuit to the motor II for the fan II. It will further be noted that the contact II of the switch II is energized, and as a result, the switch II is closed by the solenoid II to operate the condenser fan motor II.

It has been briefiy stated above that the pressure switch I3 is operated by the oil pressure within the internal combustion engine. In this connection, attention is again directed to Figure 2 of the drawing wherein it will be noted that the movable contact II of the switch is connected to an expansible chamber II and the expansible chamber in turn is connected to the oil pump of the engine. The arrangement is such that when the engine is started, pressure is built up in the expansible chamber II, and as the latter expands, it moves the switch contact 'II from the position shown in Figure 2 in engagement with the contact II to a position in engagement with the contact II to energize the solenoid II. It was also stated above that the safety switch 12 is normally in its closed position. This safety switch is connected in series with the pressure switch II and also comprises an expansible chamber II. The chamber II is connected to the condenser II. so that if the pressure in the condenser should approach an abnormal quantity, the switch I2 is automatically opened by expansion of the chamber II.

The compressor II is, of course, operated by the engine and discharges the gaseous refrigerating medium into the upper end of the condenser I3 through the conduit II. The gaseous refrigerating medium is condensed by the air circulated through the condenser and the resulting high pressure liquid flows into the receiver tank II. The liquid refrigerant fiows from the receiver tank I through the conduit II to the expansion valve I2. As the refrigerant passes through the expansion valve I2, it expands into a low pressure mixture of gas and liquid. This mixture is discharged into the receiving or upper end of the heat exchange unit II and, as the mixture passes downwardly through the latter,

accuse it absorbs heat from the air being blown or forced through the heat exchange unit by the fan II.

As the mixture absorbs heat from the atmosphere within the enclosure II. it is converted into a vaper and is still at relatively low pressure. The vapor is discharged from the heat exchange unit II through the conduit II to the auxiliary receiving tank II and passes through the conduit II to the low pressure side of the compressor II. As stated above, the valve II has previously been opened, so that it does not restrict the passage of the vapor from the tank II to the compressor. In this connection it is pointed out that the expansion valve II is restricted, so that when the valve II is open, very little or no gas flows to the evaporator II on the suction stroke or the compressor. Therefore the evaporator II may be considered as inoperative during the cooling cycle and the heat exchange unit II may be considered as the evaporator.

It will also be noted that whenever the apparatus is operated on the cooling cycle, the fan II draws air through the opening 26 and through the evaporator II. This air is directed in heat conducting relationship to the internal combustion engine to cool the same and is then discharged into the duct I2 with the exhaust gases or products of combustion. The air mixed with the products of combustion is discharged out of 30 the compartment II through the opening II.

The apparatus operates on the cooling cycle until the temperature within the enclosure II' drops below a predetermined value determined by a suitable thermostat (not shown) within-the enclosure. This thermostat in turn operates the switch 51', and the latter is connected in the circuit shown in Figure 2 of the drawing in such a manner that it automatically starts and stops the internal combustion engine in accordance with temperature fluctuations within the enclosure.

Assuming now that it is desired to heat the atmosphere within the enclosure II', the operator merely depresses the push button II on the control switch II. Also, the control arm 2I is operated to close the louvres II and the control arm 30 is operated to close the louvres 28. Closing of the louvres 2I efiects a swinging movement of the damper II to its dotted line posiopening II is closed and the duct I2 communicates with the space between the evaporator II and the louvres 2I.

Operation of the switch II by manipulating 55 the push button I! energizes the solenoid coil II to open the valve II and, of course, deenergizes the solenoid coil II to permit the valve II to close. Also, the movable contact II of the switch 51' engages the stationary contact II to energize the g latter, so that the ignition circuit and starter motor are operated in the same manner as previously described in connection with the cooling cycle. However, it is to be noted that the solenoid is deenergized so that the switch II 5 is open, and operation of the condenser fan 31 is discontinued.

When the motor is started, the compressor II discharges gaseous refrigerant under high pressure through the conduit 39 to the upper end of T0 the condenser II. This condenser, however, is inoperative due to the fact that no air is bein circulated through the same, and as a result, the refrigerant passes through the tank III and through the bypass II to the receiving end of 7 the heat exchange unit II. In this connection tion shown in Figure 1 of the drawing where the it will be noted that the valve N is open to permit relatively free flow of refrigerant to the heat exchange unit, and since the expansion valve 42 is restricted, very little or no flow takes place in the conduit 4|. As the gaseous refrigerating medium passes through the heat exchange unit ll, it gives up heat to the air being blown through the heat exchange unit by the fan It, and in this respect, the heat exchange unit may be considered as a condenser. The condensed refrigerant is discharged from the heat exchange unit through the conduit 45 into the auxiliary tank 44 and since the valve 41 is closed, the refrigerant passes through the conduit 48 and expansion valve 49 to the upper end of the evaporator l8. As the refrigerant passes through the expansion valve II, it is expanded, and the resulting low pressure mixture passes through the evaporator to the low pressure side of the compressor. As the mixture flows through the evaporator, it absorbs heat from the air and exhaust gases which are circulated through the evaporator by the fan II of the engine. The air passing through the evaporator is cooled and is then conducted into heat conducting relationship to the internal combustion engine. In this connection it will be noted that the opening It establishes permanent communication between the interior of the compartment and the atmosphere, so that exhaust gases cannot build up a pressure within the compartment. The air for mixture in the carburetor may be drawn into the compartment through a suitable flexible hose (not shown herein).

When the apparatus is operating on the cooling cycle, it may be necessary at times to defrost the heat exchange unit it, because the latter is operating as an evaporator under such conditions. When it is desired to defrost the heat exchange unit H, the operator merely depresses the push button 58 or stop button on the switch 54 to discontinue the cooling cycle. The button 51 on theswitch 54 is then operated to initiate the heating cycle, and the apparatus is operated on the heating cycle until complete defrosting has been accomplished. It may be pointed out at this time that it is not necessary to disturb the louvres 23 and 28 during the defrosting operation, since enough heat will be absorbed from the air being drawn through the opening if and evaporator ill by the engine fan 5|. 1

What I claim as my invention is:

1. Air conditioning apparatus comprising a refrigerant compressor, means for operating the compressor, a condenser for the compressed reirigerant, an evaporator having a fluid connection with the condenser for receiving the condensed refrigerant and having a fluid connection with the low pressure side of the compressor. an expansion valve in the fluid connection between the condenser and evaporator, a bypass extending around the expansion valve and connected to the input side of the evaporator, a control valve for selectively opening and closing the bypass, and means for rendering the condenser inoperative when said control valve is in its open position.

2. .Air conditioning apparatus comprising a refrigerant compressor, means for operating the compressor, a condenser for the compressed refrigerant, means for circulating air through the condenser for condensing the refrigerant, a heat exchange unit having a fluid connection with the condenser for receiving the condensed refrigerant and having a fluid connection with the low pressure side of the compressor, an expansion valve in the fluid connection between the condencar and heat exchange unit, a bypass extending around the expansion valve and connected to the input side of the heat exchange unit, a control valve in the bypass for selectively closing and I opening the latter, and means for discontinuing circulation of air through the condenser when said control valve is in its open position.

3. Air conditioning apparatus comprising a refrigerant compressor, means for operating the compressor, a condenser for the compressed reirigerant, an enclosure for the condenser having louvre controlled openings in the wall opposite the condenser for the flow of air, means for i'orcing air through the condenser to condense the reirigerant, a heat exchange unit having a fluid connection with the condenser for receiving the condensed refrigerant and having a fluid connection with the low pressure side of the compressor, an expansion valve in the fluid connection between the heat exchange unit and condenser, a bypass extending around the expansion valve, a control valve for selectively opening and closing the bypass, and means for closing said louvres and discontinuing the operation of said air forcing means when said control valve is in its open position.

4. Air conditioning apparatus comprising a refrigerant compressor, means for operating the compressor, a condenser for the compressed rei'rigerant, a heat exchange unit having a fluid connection with the condenser for receiving the condensed refrigerant and having a fluid connection with the low pressure side of the compressor for returning refrigerant to the latter, an expansion valve in the fluid connection between the condenser and heat exchange unit, an evaporator having the receiving end connected to the return side of the heat exchange unit and having the delivery side connected to the low pressure side of the compressor, a valve controlled bypass extending around the expansion valve, a second valve in the return connection from the heat exchange unit to the compressor and located between the low pressure side of the compressor and the point of connection of the receiving end of the evaporator tothe return side of the heat exchange unit, and means for selectively operating the bypass valve and said second valve to alternately open and close the same.

5. Air conditioning apparatus comprising a refrigerant compressor, means for operating the compressor, a condenser for the compressed refrigerant. a heat exchange unit having a fluid connection with the condenser for receiving the condensed refrigerant and having a fluid connection with the low pressure side of the compressor for returning refrigerant to the latter, an expansion valve in the fluid connection between the condenser and heat exchange unit, an evaporator having the receiving ,end connected to the return side of the heat exchange unit and having the delivery side connected to the low pressure side of the compressor, a valve controlled bypass extending around the expansion valve, a second valve in the return connection from the heat exchange unit to the compressor and located between the low pressure side of the compressor and the point of connection of the receiving end of the evaporator to the return side of the heat exchange unit, means for opening and closing the second valve upon successively closing and opening the bypass valve, and means rendering the condenser inoperative to condense reiriger.

ant in the open position of the bypass valve and in the closed poition of the second valve.

6. Air conditioning apparatus comprising a refrigerant compressor, means for operating the compressor, a condenser for the compressed refrigerant, a heat exchange unit having a fluid connection with the condenser for receiving the condensed refrigerant and having a fluid connection with the low pressure side of the compressor for returning refrigerant to the latter, an expansion valve in the fluid connection between the condenser and heat exchange unit, an evaporator having the receiving end connected to the return side of the heat exchange unit and having the delivery side connected to the'low pressure side of the compressor, a valve controlled bypass extending around the expansion valve, a second valve in the return connection from the heat exchange unit to the compressor and located between the low pressure side of the compressor and the point of connection of the receiving end of the evaporator to the return side of the heat exchange unit, means for selectively opening and closing the bypass valve, means for forcing air through the condenser rendered inoperative upon opening the bypass valve, and means for alternatively closing and opening the second valve upon successively opening and closing the bypass valve.

7. Air conditioning apparatus comprising a compartment having an opening through one wall. a refrigerant compressor in the compartment, an internal combustion engine for driving the compressor, an evaporator positioned in the compartment between the engine and one of said openings, means for drawing air through the said opening and evaporator and for directing the air in heat conducting relation to the engine, a duct for discharging the air through a second opening in the compartment and having an opening communicating with the space in the compartment between the evaporator and the first named opening, closure means for the first named opening movable to open and closed positions, and a damper for selectively closing the second opening and said duct opening.

8. Air conditioning apparatus comprising a compartment having an opening through one wall, a refrigerant compressor in the compartment, an internal combustion engine for driving the compressor, an evaporator positioned in the compartment between the engine and said opening, means for drawing air through the said opening and evaporator and for directing the air in heat conducting relation, to the engine, a duct for discharging the air through a second opening in the compartment and having an opening communicating with the space in the compartment between the evaporator and the first named opening, closure means for the first named opening movable to open and closed positions, a .common closure for the duct opening and the said second opening including a damper, and means responsive to movement of the closure means to open the first named opening to operate the damper to close the duct opening and responsive to movement of the closure means to close the first named opening to operate the damper to open the duct opening and close the second opening.

9. Air conditioning apparatus comprising a compartment having openings through one wall, a refrigerant compressor in the compartment, an internal combustion engine for driving the compressor, an evaporator positioned in the compartment between the engine and one of said openings, means for drawing air through the said one opening and evaporator and for directing the air in heat conducting relation to the engine, a duct for discharging the air through a second opening and having an opening communicating with the space in the compartment between the evaporator and said one opening, means for discharging the products of combustion into the duct, louvres for the said one opening movable to open and closed positions, and a damper responsive to opening said louvres to close the duct opening and responsive to closing the louvres to open the duct opening and close the said second opening.

10. Air conditioning apparatus comprising a compartment having first and second openings through opposite end walls and having a third opening through the bottom wall, a refrigerant compressor in the compartment, an internal combustion engine for driving the compressor, an evaporator positioned in the compartment between the engine and the first opening, a condenser supported in the compartment adjacent the second opening, means for drawing air into the compartment through the third opening and for forcing the air through the condenser and second opening, means for opening and closing the second opening, means for drawing air into the compartment through the first opening and evaporator and for directing the air in heat conducting relation to the engine, a duct for discharging air circulating in heat conducting relation to the engine into the atmosphere and having an opening communicating with the space in the compartment at the intake side of the evaporator, closure means for opening and closing the first opening, and a damper operable in the open position of the closure means to close the duct opening and operable in the closed position of the closure means to open the duct opening and close communication between the duct and the atmosphere.

11. Air conditioning apparatus comprising a refrigerant compressor, means for operating the compressor, a condenser for the compressed refrigerant, an enclosure for the condenser having an opening in the wall opposite the condenser for the passage of air, a heat exchange unit having a fluid connection with the condenser for receiving the condensed refrigerant and having a fluid connection with the low pressure side of the compressor, an expansion valve in the fluid connection between the heat exchange unit and the condenser, a bypass extending around the expansion valve, a control valve for selectively opening and closing the bypass, and means operable in timed relation to closing of the control valve to close the opening aforesaid in the enclosure.

HENRY O. KIRKPATRICK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,069,201 Allison Feb. 2, 1937 2,318,858 Hornaday May 11, 1943 2,341,781 Hornaday Feb. 15, 1944 2,344,215 Soling Mar. 14, 1944 2,384,210 Sunday Sept; 4, 1945 ,443,500 Goddard June 5. 11* 

